/*
 This file 'md5' is part of Firebird Integrated Solution 1.0

 Copyright (c) 2014 Lincong

 Contact:  
 Email: lincong1987@gmail.com

 QQ: 159257119

 See Usage at http://www.jplatformx.com/firebird

 Create date: 2014-07-10 15:31
 */

define(function (require, exports, module) {

	// 在网上找的目前最快的版本
	var md5 = (function () {
		function md5cycle(x, k) {
			var a = x[0],
				b = x[1],
				c = x[2],
				d = x[3];

			a = ff(a, b, c, d, k[0], 7, -680876936);
			d = ff(d, a, b, c, k[1], 12, -389564586);
			c = ff(c, d, a, b, k[2], 17, 606105819);
			b = ff(b, c, d, a, k[3], 22, -1044525330);
			a = ff(a, b, c, d, k[4], 7, -176418897);
			d = ff(d, a, b, c, k[5], 12, 1200080426);
			c = ff(c, d, a, b, k[6], 17, -1473231341);
			b = ff(b, c, d, a, k[7], 22, -45705983);
			a = ff(a, b, c, d, k[8], 7, 1770035416);
			d = ff(d, a, b, c, k[9], 12, -1958414417);
			c = ff(c, d, a, b, k[10], 17, -42063);
			b = ff(b, c, d, a, k[11], 22, -1990404162);
			a = ff(a, b, c, d, k[12], 7, 1804603682);
			d = ff(d, a, b, c, k[13], 12, -40341101);
			c = ff(c, d, a, b, k[14], 17, -1502002290);
			b = ff(b, c, d, a, k[15], 22, 1236535329);

			a = gg(a, b, c, d, k[1], 5, -165796510);
			d = gg(d, a, b, c, k[6], 9, -1069501632);
			c = gg(c, d, a, b, k[11], 14, 643717713);
			b = gg(b, c, d, a, k[0], 20, -373897302);
			a = gg(a, b, c, d, k[5], 5, -701558691);
			d = gg(d, a, b, c, k[10], 9, 38016083);
			c = gg(c, d, a, b, k[15], 14, -660478335);
			b = gg(b, c, d, a, k[4], 20, -405537848);
			a = gg(a, b, c, d, k[9], 5, 568446438);
			d = gg(d, a, b, c, k[14], 9, -1019803690);
			c = gg(c, d, a, b, k[3], 14, -187363961);
			b = gg(b, c, d, a, k[8], 20, 1163531501);
			a = gg(a, b, c, d, k[13], 5, -1444681467);
			d = gg(d, a, b, c, k[2], 9, -51403784);
			c = gg(c, d, a, b, k[7], 14, 1735328473);
			b = gg(b, c, d, a, k[12], 20, -1926607734);

			a = hh(a, b, c, d, k[5], 4, -378558);
			d = hh(d, a, b, c, k[8], 11, -2022574463);
			c = hh(c, d, a, b, k[11], 16, 1839030562);
			b = hh(b, c, d, a, k[14], 23, -35309556);
			a = hh(a, b, c, d, k[1], 4, -1530992060);
			d = hh(d, a, b, c, k[4], 11, 1272893353);
			c = hh(c, d, a, b, k[7], 16, -155497632);
			b = hh(b, c, d, a, k[10], 23, -1094730640);
			a = hh(a, b, c, d, k[13], 4, 681279174);
			d = hh(d, a, b, c, k[0], 11, -358537222);
			c = hh(c, d, a, b, k[3], 16, -722521979);
			b = hh(b, c, d, a, k[6], 23, 76029189);
			a = hh(a, b, c, d, k[9], 4, -640364487);
			d = hh(d, a, b, c, k[12], 11, -421815835);
			c = hh(c, d, a, b, k[15], 16, 530742520);
			b = hh(b, c, d, a, k[2], 23, -995338651);

			a = ii(a, b, c, d, k[0], 6, -198630844);
			d = ii(d, a, b, c, k[7], 10, 1126891415);
			c = ii(c, d, a, b, k[14], 15, -1416354905);
			b = ii(b, c, d, a, k[5], 21, -57434055);
			a = ii(a, b, c, d, k[12], 6, 1700485571);
			d = ii(d, a, b, c, k[3], 10, -1894986606);
			c = ii(c, d, a, b, k[10], 15, -1051523);
			b = ii(b, c, d, a, k[1], 21, -2054922799);
			a = ii(a, b, c, d, k[8], 6, 1873313359);
			d = ii(d, a, b, c, k[15], 10, -30611744);
			c = ii(c, d, a, b, k[6], 15, -1560198380);
			b = ii(b, c, d, a, k[13], 21, 1309151649);
			a = ii(a, b, c, d, k[4], 6, -145523070);
			d = ii(d, a, b, c, k[11], 10, -1120210379);
			c = ii(c, d, a, b, k[2], 15, 718787259);
			b = ii(b, c, d, a, k[9], 21, -343485551);

			x[0] = add32(a, x[0]);
			x[1] = add32(b, x[1]);
			x[2] = add32(c, x[2]);
			x[3] = add32(d, x[3]);

		}

		function cmn(q, a, b, x, s, t) {
			a = add32(add32(a, q), add32(x, t));
			return add32((a << s) | (a >>> (32 - s)), b);
		}

		function ff(a, b, c, d, x, s, t) {
			return cmn((b & c) | ((~b) & d), a, b, x, s, t);
		}

		function gg(a, b, c, d, x, s, t) {
			return cmn((b & d) | (c & (~d)), a, b, x, s, t);
		}

		function hh(a, b, c, d, x, s, t) {
			return cmn(b ^ c ^ d, a, b, x, s, t);
		}

		function ii(a, b, c, d, x, s, t) {
			return cmn(c ^ (b | (~d)), a, b, x, s, t);
		}

		function md51(s) {
			var n = s.length,
				state = [1732584193, -271733879, -1732584194, 271733878],
				i;
			for (i = 64; i <= s.length; i += 64) {
				md5cycle(state, md5blk(s.substring(i - 64, i)));
			}
			s = s.substring(i - 64);
			var tail = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
			for (i = 0; i < s.length; i++)
				tail[i >> 2] |= s.charCodeAt(i) << ((i % 4) << 3);
			tail[i >> 2] |= 0x80 << ((i % 4) << 3);
			if (i > 55) {
				md5cycle(state, tail);
				for (i = 0; i < 16; i++) tail[i] = 0;
			}
			tail[14] = n * 8;
			md5cycle(state, tail);
			return state;
		}

		/* there needs to be support for Unicode here,
		 * unless we pretend that we can redefine the MD-5
		 * algorithm for multi-byte characters (perhaps
		 * by adding every four 16-bit characters and
		 * shortening the sum to 32 bits). Otherwise
		 * I suggest performing MD-5 as if every character
		 * was two bytes--e.g., 0040 0025 = @%--but then
		 * how will an ordinary MD-5 sum be matched?
		 * There is no way to standardize text to something
		 * like UTF-8 before transformation; speed cost is
		 * utterly prohibitive. The JavaScript standard
		 * itself needs to look at this: it should start
		 * providing access to strings as preformed UTF-8
		 * 8-bit unsigned value arrays.
		 */

		function md5blk(s) { /* I figured global was faster.   */
			var md5blks = [],
				i;
			/* Andy King said do it this way. */
			for (i = 0; i < 64; i += 4) {
				md5blks[i >> 2] = s.charCodeAt(i) + (s.charCodeAt(i + 1) << 8) + (s.charCodeAt(i + 2) << 16) + (s.charCodeAt(i + 3) << 24);
			}
			return md5blks;
		}

		var hex_chr = '0123456789abcdef'.split('');

		function rhex(n) {
			var s = '',
				j = 0;
			for (; j < 4; j++) {
				s += hex_chr[(n >> (j * 8 + 4)) & 0x0F] + hex_chr[(n >> (j * 8)) & 0x0F];
			}
			return s;
		}

		function hex(x) {
			for (var i = 0; i < x.length; i++) {
				x[i] = rhex(x[i]);
			}

			return x.join('');
		}

		function md5(s) {
			return hex(md51(s));
		}

		/* this function is much faster,
		 so if possible we use it. Some IEs
		 are the only ones I know of that
		 need the idiotic second function,
		 generated by an if clause.  */

		var add32 = function (a, b) {
			return (a + b) & 0xFFFFFFFF;
		};

		if (md5('hello') != '5d41402abc4b2a76b9719d911017c592') {
			add32 = function (x, y) {
				var lsw = (x & 0xFFFF) + (y & 0xFFFF),
					msw = (x >> 16) + (y >> 16) + (lsw >> 16);
				return (msw << 16) | (lsw & 0xFFFF);
			}
		}
		return md5;
	})();

	var md5Blob = (function () {
		function readContent(file) {
			var chunkSize = 2 * 1024 * 1024,
				chunks = Math.ceil(file.size / chunkSize),
				chunk = 0,
				ret = '',
				deferred = $.Deferred(),
				blobSlice = file.mozSlice || file.webkitSlice || file.slice,
				loadNext, fr;

			fr = new FileReader;

			loadNext = function () {
				var start, end;

				start = chunk * chunkSize;
				end = start + chunkSize >= file.size ? file.size : start + chunkSize;

				fr.onload = function (e) {
					ret += fr.result;
					fr.result = null;
					deferred.notify((chunk + 1) / chunks);
				};

				fr.onloadend = function () {
					fr.onload = fr.onloadend = null;

					if (++chunk < chunks) {
						setTimeout(loadNext, 1);
					} else {
						fr.readAsBinaryString(new Blob(['a'], {
							type: 'text/plain'
						}));
						deferred.notify(1);
						setTimeout(function () {
							deferred.resolve(ret);
							ret = loadNext = blobSlice = file = null;
						}, 50);
					}
				};

				fr.readAsBinaryString(blobSlice.call(file, start, end));
			};

			loadNext();

			return deferred.promise();
		}

		return function (blob) {
			return readContent(blob).pipe(function (val) {
				return md5(val);
			});
		};
	})();

	module.exports = {
		md5: md5,
		md5Blob: md5Blob
	};

});